Vardenafil, also known by the brand name Levitra, is a prescription medication that treats male erectile dysfunction.
Erectile dysfunction is when a man is unable to get or sustain an erection. It usually happens because the arteries that carry the blood to the penis are too narrow.
Vardenafil increases blood flow to the penis.
Its action is similar to that of sildenafil, or Viagra, but Viagra lasts between 2 and 4 hours, while Levitra lasts 4 hours.
During a penile erection, the penis fills with blood.
The blood vessels that supply the penis with blood expand, or dilate, and the vessels that take blood away from the penis contract. The two large chambers in the penis, known as the corpus cavernosa, fill with blood.
As the blood accumulates in the penis, an erection results.
Vardenafil belongs to a class of drugs called phosphodiesterase type-5 (PDE5) inhibitors. A PDE5 inhibitor stops PDE5 from constricting the arteries.
By relaxing the arteries, vardenafil enhances blood flow when a man is sexually aroused.
The active ingredient works on the chain of reactions within the penis during arousal.
When a male is sexually aroused, nitric oxide is released into his penis, and this triggers a chain of reactions.
This causes an enzyme, guanylate cyclase, to produce cyclic guanosine monophosphate (cGMP).
cGMP regulates the contraction and dilation, or expansion, of blood vessels that carry blood to and from the penis. The chemical reaction causes the vessels that supply the penis to dilate, while those removing blood from the penis contract.
Phosphodiesterase-5 (PDE5), another enzyme breaks down or destroys cGMP.
When cGMP is destroyed, the blood vessels return to their normal size, effectively ending the erection. Vardenafil stops PDE5 from destroying cGMP. In this way, it allows cGMP to work for longer. As a result, it helps prolong an erection.
Vardenafil is available in tablets of 2.5 milligrams (mg), 5 mg, 10 mg, and 20 mg. The first dose is normally 10 mg.
A 10-mg dose of vardenafil is approximately equivalent to 50 mg of sildenafil, or Viagra. This is because the chemical composition of vardenafil is different from that of sildenafil.
Orodispersible tablets must be left to dissolve on the tongue before swallowing. They should not be taken with any kind of drink.
The drug will not work unless the man is sexually aroused, so foreplay will normally be necessary.
Vardenafil can be taken with or without food, but drinking alcohol is not advised, as it reduces the chance of getting an erection. Alcohol can also increase the risk of adverse effects.
As with all medications, adverse effects and interactions can occur when using vardenafil.
One in 10 men will experience headache.
Other common side effects include:
- stuffy or runny nose
- stomach upset
In most cases, these disappear within a few hours.
Other potentially serious symptoms include:
- ringing in the ears, or sudden hearing loss
- irregular heartbeat
- swelling in the ankles, hands, or feet
- difficulty breathing
- chest pain
The patient should stop using vardenafil if these occur.
Rarely, an allergic reaction may occur. This can lead to hives, difficulty breathing, and swelling of the face, tongue, and throat. It can lead to shock, and it can be fatal. If these symptoms appear, it should be treated as a medical emergency.
Very rare side effects may include priapism, when an erection lasts longer than 4 hours. This can damage the penis. If an erection lasts too long, the individual should seek medical attention.
Visual disturbances can happen when blood pressure drops in the eye. The individual may see a blue tinge to objects, and they may have difficulty distinguishing between the colors green and blue.
If any sudden loss of vision occurs, the individual should stop taking the medication and seek medical help immediately.
Vision problems are most likely in patients with other conditions, such as heart or coronary artery disease, diabetes, and high cholesterol. Vision problems are more likely to happen if the person smokes, or if they are aged over 50 years.
Using vardenafil with some other drugs can lead to serious adverse effects.
Possible reactions include:
- a potentially dangerous drop in blood pressure, or hypotension
A man should not use vardenafil if he is taking nitrate drugs, such as riociguat (Adempas), or other nitrate drugs for chest pain or heart problems.
It should not be used with the recreational drugs, amyl nitrate and butyl nitrate, also known as poppers.
Other drugs that may interact include, but are not limited to:
- antibiotic and antifungal medications
- other medications for erectile dysfunction
- drugs for prostate problems, blood pressure, or heart rhythm disorders
- medications for HIV or AIDS
Grapefruit juice contains a chemical that makes adverse effects more likely, so it should not be consumed while using vardenafil.
Patients should tell their doctor about all their medical conditions and any other medications or supplements they use before taking vardenafil.
This is especially important if they have:
- a deformity in the shape of the penis, such as Peyronie's disease
- a heart condition, such as arrhythmia, heart failure, or angina
- a family history of a rare heart condition known as long QT syndrome
- hearing problems
- hemophilia or some kind of bleeding problem
- hypotension (low blood pressure) or hypertension (high blood pressure)
- liver or kidney problems
- multiple myeloma, leukemia, sickle cell anemia, or some other kind of blood cell problem
- non-arteritic anterior ischemic optic neuropathy (NAION)
- damage to the retina of the eye
- stomach ulcers
- retinitis pigmentosis, a rare genetic eye disease
They should also tell the doctor if they have ever experienced priapism, a seizure, or if they have recently had a stroke or a heart attack.
Levitra is available to purchase online, but users should consider the above points and check with their health provider first.
If any adverse effects occur, users are encouraged to report them to the FDA.